extern void draw_frame(void);
extern void crawl_frame(int);
extern void init_frame(struct RastPort *, USHORT,USHORT, USHORT,USHORT);
extern void resize_frame(USHORT,USHORT, USHORT,USHORT);
extern void grid_frame(struct frame *, UBYTE);

#define erase_frame() draw_frame() /* draw mode complement => EOR frame away */

struct frame
{ USHORT x1,y1;
  USHORT x2,y2;
};